The second derivative of this quantity with respect to its thermal and mechanical natural variables 
The second derivative of this quantity with respect to its thermal and mechanical natural variables is equal to the pressure derivative of temperature by a Maxwell relation. A flow at a stagnation point is characterized by a form of this quantity equal to constant-pressure heat capacity times temperature times speed squared over two. A differential amount of this quantity may be given as the sum of (*) T dS plus V dp. This quantity may be computed as the sum of internal energy with the product of pressure and volume. For 10 points, name this thermodynamic measure of a system's heat content at a given pressure.
The second derivative of this quantity with respect to its thermal and mechanical natural variables is equal to the pressure derivative of temperature by a Maxwell relation.
enthalpy